delegation with multiple NS including localhost

[Stephane Bortzmeyer]

On Thu, Jan 08, 2004 at 12:33:31PM +0100,
 Sylvain Bertrand <Sylvain.Bertrand at supelec.fr> wrote 
 a message of 66 lines which said:

> Ok I get it. So the client's nameserver chooses the fastest between 
> ns.foo.bar.org and ns.bar.org, right?

The client's caching/forwarding nameserver chooses the fastest between
ns.foo.bar.org and ns.bar.org, right.
 
> Since ns.bar.org has no data for foo.bar.org, isn't it useless to
> delegate to itself?

I do not understand this one. If it receives a delegation, it must be
authoritative and it must have the data for foo.bar.org, either from a
local file or from a zone transfer.